1. Field of the Invention
The present invention relates to a system for manufacturing a semiconductor device, a polishing slurry feeder and a method for manufacturing a semiconductor device, and is more particularly suited for application to a system for manufacturing a semiconductor device wherein chemical mechanical polishing is carrier out, a polishing slurry feeder of chemical mechanical polishing and a method for manufacturing a semiconductor device by using chemical mechanical polishing.
2. Background Art
In recent years, a chemical mechanical polishing (CMP) technique has been in frequent use in semiconductor-manufacturing processes. In the procedure of this CMP method, a polishing slurry called merely slurry is used. Polishing characteristics are significantly varied depending on the type of polishing slurry. For the purpose of mainly monitoring a variation in polishing rate, a H2O2 densitometer is set in currently employed polishing slurry feeders to measure the concentration thereof.
However, the polishing slurry has factors of varying various polishing characteristics other than the polishing rate. In the conventional method, monitoring with a H2O2 densitometer has been made only with respect to the variation of the polishing rate, and it has been difficult to detect other polishing characteristics, e.g. polishing characteristics relating, for example, to the occurrence of scratches, dishing, erosion and defects. Under these circumstances, a difficulty has been involved in permitting good polishing characteristics to be continuedly kept because of the variation of these polishing characteristics, with the attendant problem that electric characteristics and the like of a wiring film degrade.
The invention has been made in order to solve the above problem and has for its object the detection of variations in a polishing slurry of polishing characteristics relating to scratches, dishing, erosion, defects and the like, thereby permitting good polishing characteristics to be kept continuedly.
According to one aspect of the present invention, a system for manufacturing a semiconductor device by polishing a substrate surface comprises a polishing pad, a polishing slurry feeding apparatus and a measuring apparatus. The polishing pad is for polishing the substrate surface. The polishing slurry feeding apparatus is for feeding a polishing slurry to the substrate surface. The measuring apparatus is immersed in the polishing slurry and including at least two electrodes. The measuring apparatus is arranged so that a characteristic variation of the polishing slurry is detected from a value of a current passing between the electrodes or a variation in potential difference between the electrodes.
According to another aspect of the present invention, a polishing slurry feeder for feeding a polishing slurry to a substrate polishing device comprises a measuring apparatus. The measuring apparatus is immersed in the polishing slurry and including at least two electrodes. The measuring apparatus is arranged so that a characteristic variation of the polishing slurry is detected from a value of a current passing between the electrodes or a variation in potential difference between the electrodes.
According to another aspect of the present invention, a method for manufacturing a semiconductor device using a semiconductor manufacturing system is provided. The system comprises a polishing pad, a polishing slurry feeding apparatus and a measuring apparatus. The polishing pad is for polishing the substrate surface. The polishing slurry feeding apparatus is for feeding a polishing slurry to the substrate surface. The measuring apparatus is immersed in the polishing slurry and including at least two electrodes. The measuring apparatus is arranged so that a characteristic variation of the polishing slurry is detected from a value of a current passing between the electrodes or a variation in potential difference between the electrodes.
According to the present invention, when a variation in value of a current passing between the electrodes immersed in a polishing slurry or a variation in difference of a potential between the electrodes is detected, the variation in chemical reaction quantity of the electrodes and the polishing slurry can be detected, enabling the characteristics of the polishing slurry to be detected.
According to the present invention, since the variation in characteristics of the polishing slurry can be suppressed, scratches, dishing, erosion, defects and the like are suppressed from occurring, ensuring the manufacture of a semiconductor device of high reliability.
Other and further objects, features and advantages of the invention will appear more fully from the following description.